Summary of Significant Accounting Policies - Additional Information (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2015 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Minimum corporation reserves for commercial loan	$ 500
Number of days past due for loan to be in default	90 days
Core deposit intangibles amortization period, years	10 years
Largest amount recognized in the financial statement of tax benefit threshold, minimum	Greater than 50%
Installment Loans [Member]
Summary Of Significant Accounting Policies [Line Items]
Number of days placed on non-accrual	120 days
Residential Mortgages [Member]
Summary Of Significant Accounting Policies [Line Items]
Number of days placed on non-accrual	180 days
Commercial Loans [Member]
Summary Of Significant Accounting Policies [Line Items]
Number of days placed on non-accrual	90 days
Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Useful life of the asset, years	3 years
Estimated useful life of intangibles, years	8 years
Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Useful life of the asset, years	40 years
Estimated useful life of intangibles, years	13 years